1. Field of the Invention
The present invention relates to an optical switch for a very large number of channels, especially for switching the channels of a telephone exchange.
2. Description of the Prior Art
The switching systems presently used in telephone exchanges are either electromechanical or electronic, but even in the case of electronic exchanges, the size of the switch must be increased in order to obtain a very large number of switching possibilities, which is not always desirable.
In addition, because of the likely decrease in natural copper sources and the ever increasing requirement for data transmission channels, the manufacturers of data transmission lines have been prompted to envisage the use of an optical carrier guided by a glass filament, this solution appearing to be the most promising at the present time.
Many of the components for constituting an optical network, such as low-loss glass filaments, sources, detectors, couplers, modulators, deflectors, etc., are already in an advanced stage of development. On the other hand, the switching systems, which nevertheless constitute one of the essential parts of a telecommunications network, are presently at the very beginning of their development and their performance characteristics are far from reaching those of electronic switching systems.